{"abstract":"A checkpoint beyond local file size must be discarded before a range request.","category":"HTTP ranges","checks":6,"contract":"Return checkpoint if checkpoint<=file_size else zero; nonnegative integers. Extra uncheckpointed file bytes do not advance checkpoint.","contract_signature":"checkpoint, file_size","evaluation_group":"s3-http_ranges-resume-client","failed_approach":"The partial repair uses return min(checkpoint,file_size), which still violates the stated contract.","family":"s3-http_ranges-resume-local-file-truncation","id":"FA-26771","implementations":{"attempt":{"sha256":"400150d5c96ca2c8a86c865a33dee2d473a270f4ae5c5c660a66dc2ae68c1e1a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(checkpoint, file_size):\n    return min(checkpoint,file_size)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-local-file-truncation fixture 0', solve(N+1,N), 0)\ncheck('resume-local-file-truncation fixture 1', solve(N,2*N), N)\ncheck('resume-local-file-truncation fixture 2', solve(N,N), N)\ncheck('resume-local-file-truncation fixture 3', solve(0,N), 0)\ncheck('resume-local-file-truncation fixture 4', solve(N,0), 0)\ncheck('resume-local-file-truncation fixture 5', solve(0,0), 0)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"a580d83d85ed18b1452ef2c7de4739e4b9f77b725596291c322b656efa15f261","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(checkpoint, file_size):\n    return checkpoint\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-local-file-truncation fixture 0', solve(N+1,N), 0)\ncheck('resume-local-file-truncation fixture 1', solve(N,2*N), N)\ncheck('resume-local-file-truncation fixture 2', solve(N,N), N)\ncheck('resume-local-file-truncation fixture 3', solve(0,N), 0)\ncheck('resume-local-file-truncation fixture 4', solve(N,0), 0)\ncheck('resume-local-file-truncation fixture 5', solve(0,0), 0)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-http_ranges-resume-local-file-truncation","generated_at":"2026-09-29T14:41:18.929919+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","root_cause":"The resume-local-file-truncation decision uses return checkpoint.","sha256":"f230e2f8314d18c0c831c6984843bcfd7fe33e0b61455e2572298a6584884477","title":"A checkpoint beyond local file size must be discarded before a range request · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":37.244,"exit_code":1,"observations":[{"actual":1,"check":"resume-local-file-truncation fixture 0","expected":0,"passed":false},{"actual":1,"check":"resume-local-file-truncation fixture 1","expected":1,"passed":true},{"actual":1,"check":"resume-local-file-truncation fixture 2","expected":1,"passed":true},{"actual":0,"check":"resume-local-file-truncation fixture 3","expected":0,"passed":true},{"actual":0,"check":"resume-local-file-truncation fixture 4","expected":0,"passed":true},{"actual":0,"check":"resume-local-file-truncation fixture 5","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-local-file-truncation fixture 0\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"resume-local-file-truncation fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 5\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.37,"exit_code":1,"observations":[{"actual":2,"check":"resume-local-file-truncation fixture 0","expected":0,"passed":false},{"actual":1,"check":"resume-local-file-truncation fixture 1","expected":1,"passed":true},{"actual":1,"check":"resume-local-file-truncation fixture 2","expected":1,"passed":true},{"actual":0,"check":"resume-local-file-truncation fixture 3","expected":0,"passed":true},{"actual":1,"check":"resume-local-file-truncation fixture 4","expected":0,"passed":false},{"actual":0,"check":"resume-local-file-truncation fixture 5","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-local-file-truncation fixture 0\", \"actual\": 2, \"expected\": 0, \"passed\": false}, {\"check\": \"resume-local-file-truncation fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"resume-local-file-truncation fixture 4\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"resume-local-file-truncation fixture 5\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}